Low Sperm Count is helped by Vitamin B12

Low Sperm Count is helped by Vitamin B122022-04-25T16:55:02-07:00

For LOW SPERM COUNT, vitamin B12 plays a critical role in cell replication and sperm formation, and so a deficiency can result in low sperm count. Vitamin B12 is essential for DNA production and sperm health and development, and thus for male fertility. Vitamin B12 is also needed for red blood cell formation and maturation, normal functioning of the brain and nervous system, and for maintaining critical DNA synthesis and activity in every cell.

For fifty years, scientists have been investigating the important effects of B12 supplementation on sperm count. It is now apparent that deficiencies in this vitamin lead to genetic damage of sperm cells, causing infertility. Vitamin B12, or cobalamin, is a water-soluble vitamin that is involved in the metabolism of every cell of the human body. Neither fungi, plants, nor animals can make vitamin B12. Many people have a dietary B12 deficiency, as it is only prevalent in red meats, organ meats like liver, and eggs. Additionally, modern diets are typically saturated with highly processed foods and consequently low vitamin B12 intake is common. Vegan and vegetarian men receive little or no vitamin B12 in their diets.

And then, even if vitamin B12 is consumed, its absorption is fraught with hurdles: First, in the stomach, vitamin B12 requires sufficient acid to release it from protein foods. Then it needs to bind with a protein called Intrinsic Factor to become absorbable. Next this B12-Intrinsic Factor complex must travel all the way through the small intestine to a small area at the far end, the terminal ileum, where it can pass into the blood stream. Any stomach disorders with reduced acid production, or pernicious anemia where Intrinsic Factor is lacking can prevent B12 absorption. Intestinal inflammation such as Crohn’s disease, where a damaged terminal ileum cannot take up vitamin B12, also contributes to deficiency.

Studies show that sperm count rebounds promptly with generous doses of vitamin B12. In one study, men with abnormal sperm counts of less than 20 million/ml were given 1000 mcg per day of vitamin B12: Their sperm counts soon showed a significant increase to an average in excess of 100 million/ml.1

Vitamin B12 appears to play an important role in the development of sperm, known as spermatogenesis, in very young mammals. In a 2003 study, a vitamin B12-deficient diet was given to animals for three different time spans: whole period of observation (gestation to mature), gestation period (gestation to weaning), or immature period (3-12 weeks old). Sperm examination revealed that sperm counts were markedly lower in males who were vitamin B12-deficient during the whole period, from their fetal stage through adulthood. In addition, a significantly higher number of abnormal sperm, such as tailless and amorphous sperm, was observed in B12-deficient individuals. For males who were vitamin B12-deficient during the immature period, the incidence of abnormal sperms was 14.4% for tailless and 4.8% short tail deformities. Sperm motility, such as path velocity and straight-line velocity, were decreased way down to 20-40% of the control value in males who were vitamin B12-deficient throughout the whole period from gestation onwards. In conclusion, researchers surmised that dietary vitamin B12 deficiency during pregnancy may affect male embryos before their birth, inducing irreversible damage in the germ cells of male embryos, and impeding the maturation of spermatozoa in adult life. 2

In a Japanese study, researchers administered 1,500 mcg per day of vitamin B12 in its methylcobalamin form orally to men for between two and thirteen months. Of the men receiving B12, 60% experienced improved sperm counts. The longer the period of supplementation, the more stable and enduring were the higher sperm counts.3

A meta-analysis of all studies from 1961 to 2017 was published summarizing the currently understood role of vitamin B12 on semen quality and sperm physiology. The paper’s author concluded that published studies, including 23 clinical in vivo, and in vitro trials, demonstrated positive effects for vitamin B12 on semen quality: primarily increasing total sperm count, and secondarily enhancing sperm motility and reducing sperm DNA damage. As a result, vitamin B12 typically at “normal or therapeutic doses,” is proven to be vital for adequate semen quality. The author attributed vitamin B12’s favorable effects on semen quality “to several mechanisms of action:

  1. Increased efficacy of male reproductive organs,
  2. Decreased homocysteine toxicity,
  3. Increased nitric oxide production;
  4. Decreased accumulation of reactive oxygen species;
  5. Reduced energy production by spermatozoa;
  6. Decreased inflammation-induced semen impairment, and
  7.  Control of nuclear factor-κB activation.” 4

Since vitamin B12 is the largest and most structurally complicated of the B vitamins, and absorption can be problematic, we give our patients a formula that that circumvents the stomach so that B12 can efficiently reach the blood stream. Studies as early as 1998 validate that correct oral treatment is equally effective as injections, with this conclusion: In cobalamin (vitamin B12) deficiency, 2,000mcg of cyanocobalamin administered orally on a daily basis was as effective or even superior for raising blood B12 levels compared to 1,000mcg administered intramuscularly each month. This proves to be an important treatment for raising sperm counts.5

In our clinic, we see excellent and rapid improvements in blood B12 levels with a sublingual vitamin B12 that dissolves slowly under the tongue, and our male patients experience significant increases in sperm counts over time. We recommend a lozenge formulation with only natural flavorings, best taken in the morning or afternoon as it may cause a quick energy boost. We like to use a vitamin B12 that is combined and balanced with an ample amount of folic acid, which should always be included with vitamin B12 to make sure that a folic acid deficiency is not masked.

Vitamin B-12 (as cyanocobalamin) 2,500 to 5,000mcg combined with Folic Acid at least 400mcg, dissolved slowly under the tongue, once daily in the morning or early afternoon, or as directed by your healthcare provider. Sublingual B12 usually takes 10 to 15 minutes to dissolve, but if it takes longer we recommend that patients bite it into pieces, then let those fragments melt under the tongue.


  1. Sandler B, Faragher B. (1984). Treatment of oligospermia with vitamin B12. Infertility, Volume 7:133–8.
  2. Watanabe, Toshiaki, et al. “The effects of dietary vitamin B12 deficiency on sperm maturation in developing and growing male rats.” Congenital anomalies 43.1 (2003): 57-64.
  3. Isoyama, R., et al. “Clinical experience with methylcobalamin (CH3-B12) for male infertility.” Hinyokika kiyo. Acta urologica Japonica 30.4 (1984): 581-586.
  4. Banihani, Saleem Ali. “Vitamin B12 and Semen Quality” Biomolecules vol. 7,2 42. 9 Jun. 2017.
  5. Kuzminski AM, Del Giacco EJ, et al. Effective treatment of cobalamin deficiency with oral cobalamin. Blood 1998;92:1191-1198.
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